arbiter-commandquery

Arbiter.CommandQuery

CQRS layer on top of Arbiter.Mediation: pre-built generic commands/queries for entity CRUD, plus filter/sort/page modeling and opt-in behaviors.

Install

dotnet add package Arbiter.CommandQuery

A data provider package supplies the handlers — pick one:

• Arbiter.CommandQuery.EntityFramework → see arbiter-commandquery-ef
• Arbiter.CommandQuery.MongoDB → see arbiter-commandquery-mongo

Register

using Arbiter.CommandQuery;

services.AddCommandQuery();              // core CQRS pipeline + mediator
services.AddCommandValidation();         // optional: FluentValidation pipeline behavior
services.AddEntityHybridCache();         // optional: HybridCache-backed query caching
services.AddMessagePackOptions();        // optional: configure MessagePack for dispatcher

Built-in commands and queries

Type	Purpose
EntityIdentifierQuery<TKey, TReadModel>	Get one by id
EntityIdentifiersQuery<TKey, TReadModel>	Get many by ids
EntityPagedQuery<TReadModel>	Filter + sort + (optional) page
EntityCreateCommand<TCreateModel, TReadModel>	Insert
EntityUpdateCommand<TKey, TUpdateModel, TReadModel>	Update; pass upsert: true for upsert
EntityPatchCommand<TKey, TReadModel>	JSON Patch partial update
EntityDeleteCommand<TKey, TReadModel>	Delete

All commands/queries take a ClaimsPrincipal as the first ctor arg.

Canonical pattern — paged query with filter + sort

using Arbiter.CommandQuery.Queries;

var entityQuery = new EntityQuery
{
    Filter = new EntityFilter
    {
        Logic = FilterLogic.And,
        Filters = new List<EntityFilter>
        {
            new() { Name = "Category", Operator = FilterOperators.Equal,       Value = "Electronics" },
            new() { Name = "Price",    Operator = FilterOperators.GreaterThan, Value = 100m },
        }
    },
    Sort = new List<EntitySort>
    {
        new() { Name = "Name", Direction = SortDirections.Ascending }
    },
    Page = 1,
    PageSize = 20,   // omit Page/PageSize to return all matches
};

var query  = new EntityPagedQuery<ProductReadModel>(principal, entityQuery);
var result = await mediator.Send(query, cancellationToken); // EntityPagedResult<ProductReadModel>

Variations

// Get by id
var product = await mediator.Send(
    new EntityIdentifierQuery<int, ProductReadModel>(principal, id), ct);

// Create
var created = await mediator.Send(
    new EntityCreateCommand<ProductCreateModel, ProductReadModel>(principal, createModel), ct);

// Update (upsert with last bool)
var updated = await mediator.Send(
    new EntityUpdateCommand<int, ProductUpdateModel, ProductReadModel>(principal, id, model, upsert: true), ct);

// Delete
var deleted = await mediator.Send(
    new EntityDeleteCommand<int, ProductReadModel>(principal, id), ct);

Filter operators (enum, v2.0+)

FilterOperators: Equal, NotEqual, LessThan, LessThanOrEqual, GreaterThan, GreaterThanOrEqual, Contains, StartsWith, EndsWith, In, NotIn, IsNull, IsNotNull. FilterLogic: And, Or. SortDirections: Ascending, Descending.

Behaviors (opt-in via marker interfaces on the entity / model)

Behavior	Triggered by
Validation	services.AddCommandValidation() + a FluentValidation.IValidator<TRequest>
Hybrid cache	services.AddEntityHybridCache() + [Cacheable] on the query/read-model
Audit fields	Entity implements ITrackCreated / ITrackUpdated
Soft delete	Entity implements ITrackDeleted — paged queries auto-filter
Tenant isolation	Entity implements IHaveTenant<TKey>

Add per-entity behavior registrations only if you need extra pipeline stages beyond what AddEntityQueries / AddEntityCommands already wires:

services.AddEntityQueryBehaviors<int, ProductReadModel>();
services.AddEntityCreateBehaviors<int, ProductReadModel, ProductCreateModel>();
services.AddEntityUpdateBehaviors<int, ProductReadModel, ProductUpdateModel>();
services.AddEntityPatchBehaviors<int, Product, ProductReadModel>();
services.AddEntityDeleteBehaviors<int, Product, ProductReadModel>();

Reference

• Guide: https://github.com/loresoft/Arbiter/blob/main/docs/guide/commandQuery.md
• Queries: https://github.com/loresoft/Arbiter/tree/main/docs/guide/queries
• Commands: https://github.com/loresoft/Arbiter/tree/main/docs/guide/commands
• Behaviors: https://github.com/loresoft/Arbiter/tree/main/docs/guide/behaviors